In underground mining, hydraulic cylinders are frequently used as telescopic pit props or moving cylinders in self-advancing supports.
In such hydraulic cylinders, a sleeve holder is commonly screwed into a cylinder tube or, in case of a telescopic pit prop, an outer cylindrical tube and an inner cylindrical tube. The sleeve holder serves to support and guide the inner cylindrical tube and/or the piston rod, and receives and transfers forces from the piston rod to the cylinder tube, or from the piston rod to the inner cylindrical tube and from the inner cylindrical tube to the outer cylindrical tube. In addition, the sleeve holder seals the annular space formed between the corresponding elements. Further, the sleeve holder commonly includes grooves and the like for receiving sealing gaskets for sealing the annular space.
It has been found that, as a consequence of the rough operating conditions underground, the sleeve holder may come loose due to the forces applied to and transferred by the same. Therefore, it is necessary to secure the sleeve holder to the cylinder tube of a cylinder and the outer and/or inner cylindrical tube of a telescopic pit prop. An example for a method of securing a sleeve holder to a hydraulic cylinder is shown in U.S. Pat. No. 6,615,705 B2.
The disclosed systems and methods are directed at least in part to improving known systems.